A cell type-specific cortico-subcortical brain circuit for investigatory and novelty-seeking behavior

Exploring the physical and social environment is essential for understanding the surrounding world. We do not know how novelty-seeking motivation initiates the complex sequence of actions that make up investigatory behavior. We found in mice that inhibitory neurons in the medial zona incerta (ZIm), a subthalamic brain region, are essential for the decision to investigate an object or a conspecific. These neurons receive excitatory input from the prelimbic cortex to signal the initiation of exploration. This signal is modulated in the ZIm by the level of investigatory motivation. Increased activity in the ZIm instigates deep investigative action by inhibiting the periaqueductal gray region. A subpopulation of inhibitory ZIm neurons expressing tachykinin 1 (TAC1) modulates the investigatory behavior.

Automated summary

Inhibitory neurons in the medial zona incerta (ZIm) of mice play a crucial role in deciding whether to investigate the surroundings or another individual. These neurons receive excitatory input from the prelimbic cortex to initiate and regulate exploratory behavior. The level of investigatory motivation modulates this neural activity in ZIm, influencing the depth of investigative actions.